Growing emphasis on simulation of low altitude and air-to-air tactical scenarios has greatly increased the requirement for simulator visual systems capable of providing the pilot high-fidelity out-of-the-cockpit cues. Evaluation of visual system performance through simulator flying studies has been the primary measure of system quality. Such Studies can be costly and time consuming, and often they provide equivocal results. The present set of experiments was conducted to investigate the use of psychophysical measurement methodology to provide a quick, low-cost evaluation of the altitude cueing effectiveness of simulator visual displays. Experiment I examined altitude perception in several visual environments. Experiment II was a validation effort, in which flying performance was evaluated in selected visual environments. In Experiment I pilots made altitude estimates based on static and dynamic presentations of visual displays containing texture and varying sizes of 3-dimensional objects. Best-fitting power functions were used to relate perceived altitude to actual altitude. In Experiment II Air force pilots flew the Advanced Simulator for Pilot Training F-16 through five selected visual environments at 600 kt and 150 ft AGL. Reliable difference were found as a function of display variables. In environments which provided strong altitude cues, pilots were able to fly very close to the designated altitude. In environments which provided poorer cues, pilots flew substantially above designated altitude.